Apparatus for measuring tensile and breaking strength.



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L. SGHOPPER.

APPARATUS FOR MEASURING TENSILE AND BREAKING STRENGTH APPLICATION FILEDJUNE 11, 1910.

990,302. Patented Apr. 25, 1911.

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LOUIS SCHOPPER, OF LEIPZIG, GERMANY.

APPARATUS FOR MEASURING TENSILE AND BREAKING STRENGTH.

Specification of Letters Patent.

Patented Apr. 25, 1911.

Application filed June 11, 1910. Serial No. 566,329.

To all whom it may concern:

Be it known that I, LOUIS Sorrorrnn, a subject of the King of Saxony,residing at Leipzig, in Germany, have invented a certain new and usefulApparatus for Measuring Tensile and Breaking Strength, of which thefollowing is a specification.

This invention relates to apparatus for measuring tensile strength, ofthe class wherein means are provided for indicatlng the extension of thetest-piece at the moment of fracture.

The object of the invention is to provlde apparatus which enables thetwo readings (tensile strength and extension) to be obtained by anoperation more rapid and mmple than with the apparatus heretofore known.

The invention is illustrated in the annexed drawings in which- Figure 1is a longitudinal sectional elevation of part of the apparatus, Fig. 2plan view thereof, Fig. 3 a side view of part of the mechanism and Fig.4 is a detail to be referred to.

The apparatus comprises a slide or car riage 2 movable on a bed 1. A rod7 movable in this slide, is attached at one end thereto by a spring 20,see Fig. 4, wherein it will be seen that one end of said spring isconnected to the rod 7 and the other end to one end of a bar 21, theopposite end of said bar being threaded to receive upon it a nut 22which is held by the spring in engagement with the end of the slide orcarriage 2, thereby providing for longitudinal adjustment of said barfor the purpose of adjusting the spring 20. The bar 21 has a pin 23extended from it which enters a slot 24 in the slide or carriage 2, topermit longitudinal adjustment of said bar and to prevent rotation ofsaid bar by turning the nut clamp 6 for engaging one end of thetest-piece. A clamp 9 for engaging the other end of the testpiece isfixed to the bed 1. A scale 10, for readings of extension, is fixed tothe bed. The indicator 11 and tensile strength scale 12 are movablerelatively thereto, the scale 12 being fixed to a bar 14 slidable on thebed and the slide 11 of the indicator 11 having sliding movement withsome friction on the bar 14. This bar 14 can be engaged with thecarriage 2 by the engagement of its hooked end 14 with the hook 17 of abell-crank 17 pivoted at 17 to the carriage 2, so that the bar 14 andscale 12 travel through the same distance as the carriage 2 during thestretching of the test-piece. A rod 15 is pivoted at 15 to the clampinghead 6 and has sliding movement on the side of the upper arm of thebell-crank 17. The rod 15 has at a suitable place along its length ashoulder 16 adapted to abut against the bell-crank when the clamp 6 ishome against the end of the carriage 2 and thus rock the bell-crank anddisengage the hooks 14 17. The slide 11 carrying the indicator 11 hasabutment against some part of the clamp 6 as for instance against thepivot 15 (see Fig. 3).

A test-piece having been clamped in the clamps 6, 9, the carriage 2 ismoved to the right. An outward pull of increasing force is thus exertedthrough the spring (not shown) on the clamp 6. The rod 14 and scale 12move equally with the carriage 2 and the indicator 11 is carried alongby friction so far therewith as the abutment of its slide 11 against theclamp 6 permits. Under the pull of the spring the test-piece sufferselongation the amount of which is indicated on the scale 10 by theindicator 11. At the moment of fracture of the test-piece, the clamp 6flies suddenly against the end of carriage 2 thus causing the rod 15 torock the bell-crank 17 and disengage the hooks 14 17 a so that nofurther movement is given to the rod 14. The indicating line of theindicator 11 then shows the extension on the scale 10 and the tensilestrength on the scale 12. Both readings can be taken at a single glance,as they are in the same field of view, but since they appear on separatescales there is no liability to confusion.

What I claim as my invention and desire to secure by Letters Patent ofthe United States is In apparatus for indicating extension and tensilestrength, the combination of a bed, a fixed clamp, a movable clamp, acarriage having spring connection with the movable clamp, a bell-cranklever carried by thecarriage and having a hooked arm, a draw rod adaptedto engage the hooked arm, a tenslle strength scale attached to said rod,a sliding specification in the presence of tWo Witindicator on said rod,agapted to have abutnesses. Inent a ainst the move 1e 0 am an eXtenvsion sc ie on the bed, and a ro d connected LOUIS SGHOPPER' 5 to saidmovable clamp and adapted to have Witnesses:

disconnecting action on the bell-crank lever. RUDOLPH FRIOKE,

In Witness whereof I have signed this I GURT LEHMANN.

Copies of this patent may be obtained for five cents each, by addressingthe Commissioner of Patents,

Washington, D. G.

